In 1806 Josephine accompanied Napoleon on the Prussian
Campaign, but a dark cloud was looming on the horizon:
left behind in France was his latest mistress, Eleonore
Denuelle, who was pregnant with his child. Until this
time Napoleon had thought Josephines barrenness
during their marriage might be his fault, but the birth
of his son to Eleonore Denuelle changed everything.
While he still loved Josephine, he began to think very
seriously again about the possibility of divorce.

CHEVALLIER:
Their greatest quarrels were jealousy, because
Josephine was extremely jealous. She knew that she
couldnt have any children and I think she learned
that very early and she tried to make Napoleon believe
that he couldnt have any. She said, "Ive
already had two, you havent had any," so
she tried to make him believe that, but she knew there
was a threat hanging over her head because if she
were to be divorced, then she would have lost everything
shed attained. And Napoleon had flirts as it
were with women around him, but she was so jealous
that sometimes she would spy on the emperor and go
up back staircases and listen at the doors. This is
something which made their life very difficult because
Napoleon couldnt stand having her watching over
his shoulder whenever he had an adventure with another
woman.

Napoleon
wrote to his brother Lucien:

Josephine
is decidedly old and as she cannot now have any children
she is very melancholy about it and tiresome. She
fears divorce or even worse...Just imagine, the woman
cries every time she has indigestion, because she
says she believes she has been poisoned by those who
want me to marry someone else. It is detestable.

HORNE:
There's a famous rather poignant exchange between
him and Josephine in 1808, when he's getting involved
in Spain and she says, "Why on Earth do you want to
go on fighting battles?" And he says, "Because I am
a victim of history. I have no option."

The
final die was cast when Josephines grandson Napoleon,
who had been declared Napoleons heir, died of
croup in 1807. Napoleon began to create lists of eligible
princesses. At dinner on November 30, 1809, he let Josephine
know that  in the interest of France  he
must find a wife who could produce an heir. From the
next room, Napoleons secretary heard the screams.

"No,
I can never survive it!" Josephine cried, and collapsed.
The following day servants took her possessions to Malmaison,
which was to remain her home. She continued to make
public appearances as Empress, but the impending divorce
was common knowledge. The divorce ceremony was a grand
but solemn social occasion, and each read a statement
of devotion to the other.

Far
from ever finding cause for complaint, I can to the
contrary only congratulate myself on the devotion
and tenderness of my beloved wife. She has adorned
thirteen years of my life; the memory will always
remain engraved on my heart.

Josephine
replied:

With
the permission of our august and dear husband, I must
declare that, having no hope of bearing children who
would fulfill the needs of his policies and the interests
of France, I am pleased to offer him the greatest
proof of attachment and devotion ever offered on this
earth.